Seth Wilbur Moulton (born October 24, 1978) is an American politician and Marine Corps combat veteran who has been the U.S. representative for Massachusetts's 6th congressional district since 2015. A member of the Democratic Party, his district includes many of Boston's northern suburbs, such as Andover, Marblehead, Peabody, and his hometown of Salem.

After graduating from Harvard College in 2001 with a bachelor of science in physics, Moulton joined the United States Marine Corps. He served four tours in Iraq and then earned his master's degrees in business and public administration in a dual program at Harvard. He entered politics in 2014, when he was elected to represent Massachusetts's 6th congressional district.

In November 2018, Moulton spearheaded an effort to oust Nancy Pelosi as House Democratic leader. Despite Moulton's efforts, Pelosi easily won the Democratic nomination for Speaker of the House on November 28, 2018, by a 203-to-32 vote of the Democratic caucus.

On April 22, 2019, Moulton announced he would pursue the Democratic nomination for president in the 2020 election. Moulton campaigned across Iowa, New Hampshire, and South Carolina during early 2019. Moulton's presidential campaign failed to garner support and he did not qualify for the primary debates. Moulton withdrew from the presidential race on August 23, 2019.

On October 15, 2025, Moulton announced his candidacy in the 2026 U.S. Senate election in Massachusetts, challenging incumbent Ed Markey in the Democratic primary. Moulton lost to Markey on September 1, 2026.

Early life, education, and commission Moulton was born on October 24, 1978, in Salem, Massachusetts, to Lynn Alice (née Meader), a secretary, and Wilbur Thomas Moulton, Jr., a real-estate attorney. He has two younger siblings, Eliza and Cyrus, and grew up in Marblehead, Massachusetts. He graduated from Phillips Academy in 1997, and attended Harvard College, where he earned a bachelor of science in physics in 2001. He gave the Undergraduate English Oration at his commencement, focusing on the importance of service.

Moulton joined the Marine Corps after graduation, a few months before the September 11 attacks. He attended the Officer Candidate School in Quantico, Virginia, and graduated in 2002 with the rank of second lieutenant. After he left the Marine Corps in 2008, Moulton attended a dual-degree program at the Harvard Business School and the Harvard Kennedy School, earning master's degrees in business and public policy in 2011. While a graduate student at Harvard, Moulton was a resident tutor in Quincy House.

Military career During the 2003 invasion of Iraq, Moulton led one of the first infantry platoons to enter Baghdad. He served a total of four tours of duty in Iraq from 2003 to 2008. Moulton took part in the 2003 Battle of Nasiriyah, leading a platoon that cleared a hostile stronghold. In that action, he went to the aid of a Marine wounded by friendly fire, and for his actions was awarded the Navy and Marine Corps Commendation Medal for valor. Moulton was active in combat against insurgent forces in Iraq, including the 2004 Battle of Najaf against the militia of Muqtada al-Sadr. Over two days, he "fearlessly exposed himself to enemy fire" as his platoon was pinned down under heavy fire and then directed the supporting fire that repelled the attack. He received the Bronze Star Medal for his actions in this battle.

In 2008, during Moulton's fourth tour of duty in Iraq, General David Petraeus requested that he be assigned to work as a special liaison with tribal leaders in southern Iraq. After that tour, Moulton was discharged from the Marine Corps with the rank of captain.

Media contributions In 2003, Moulton co-hosted a television program with his Iraqi interpreter, Mohammed Harba, called Moulton and Mohammed, in which they discussed regional conditions in the period following the U.S. invasion before an audience of U.S. servicemen and Iraqi citizens. The show ended after three months when Moulton's unit left the area.

Between 2003 and 2008, Moulton was frequently interviewed about his experiences as an officer in Iraq by U.S. national media, including CNN, MSNBC, and NPR programs Morning Edition and All Things Considered.

Moulton was also prominently featured in the 2007 Academy Award-nominated documentary No End in Sight. In the film, he criticizes the U.S. government's handling of the occupation of Iraq. Director Charles H. Ferguson chose to include Moulton and two other Iraq veterans.

Private sector career After graduate school, he worked for one year as managing director of the Texas Central Railway, a transportation firm. In 2011, Moulton and a graduate-school classmate founded Eastern Healthcare Partners. The company raised investor funds and drafted a partnership agreement with Johns Hopkins School of Medicine, but in October 2014, the Boston Globe reported that by the time Moulton ran for Congress, EHP had no revenue, was still incubating, and had closed its only Massachusetts office.

U.S. House of Representatives Elections 2012 speculation Moulton considered running against Democratic Representative John F. Tierney of Massachusetts's 6th congressional district as an independent in 2012, but decided against it in July 2012, saying, "the time and the logistics of putting together all the campaign infrastructure, organizing the volunteers ... the fundraising—it's just too much to accomplish in three months." He told Roll Call that his own polling "showed there was in fact a clear path to victory" and said he might run for office in the future.

2014 election

On July 8, 2013, Moulton announced his candidacy in the 2014 congressional race for Massachusetts's 6th district. The race had been recognized for its competitiveness by national and regional media throughout the election cycle. Moulton challenged Tierney in the Democratic primary.

Tierney's campaign claimed in campaign advertisements that Moulton received campaign contributions from a New Hampshire political action committee that previously donated only to Republicans, implying that Moulton must hold conservative views. Moulton denied being more conservative than Tierney, and said that the Republican PAC donation was returned. Public Federal Election Commission filings confirmed that the donation was returned in February 2014.

Moulton said that he opposed the Iraq War in which he served. A Tierney campaign staff member said that Moulton had "changed his mind" on the war, and highlighted Tierney's vote in Congress to oppose the 2002 resolution authorizing the U.S. Invasion of Iraq from the start. Moulton also received Retired General Stanley McChrystal's first-ever political endorsement during the campaign.

Moulton won the primary with 50.8% of the vote to Tierney's 40.1%.

For the general election, Moulton was endorsed by Senator Elizabeth Warren. In October 2014, he received criticism from his Republican opponent when he withdrew from a debate sponsored by radio station WGBH to instead attend a series of New York fundraisers hosted by Democratic National Committee chairwoman Debbie Wasserman Schultz.

The campaigns of Moulton and his Republican opponent, state Senator Richard Tisei, were held up as an example of a race where voters could respect both candidates and choose the better one, instead of having to choose the less undesirable one.

Moulton won the general election with 55.0% of the vote to Tisei's 41.1%.

2016 election Moulton was unopposed for reelection in 2016.

2018 election Moulton ran against Republican nominee Joseph Schneider in 2018. He won with 65.2% of the vote. In 2018 Moulton created the Serve America PAC, which helped elect Democratic candidates with national service experience.

2020 election Moulton faced his first primary challenge since taking office. He defeated Democratic challengers Angus McQuilken and Jamie Belsito with 78% of the vote, and defeated Republican nominee John Paul Moran with 65.4% of the vote.

2022 election Moulton faced Republican nominee Bob May in 2022. He won with 62.9% of the vote. Moulton refused to debate May, calling him an "election denier," citing the Republican candidate's refusal to recognize that President Joe Biden had won the 2020 presidential election.

2024 election Moulton ran for re-election in 2024. He was unopposed and won re-election.

Tenure Moulton was sworn into the 114th United States Congress on January 3, 2015.

Challenge to Nancy Pelosi as House Democratic Leader After the Democrats captured a majority in the House of Representatives in the 2018 midterm elections, Moulton spearheaded an effort to oust Nancy Pelosi as House Democratic leader and called for a "new generation of leadership". Moulton stated he was "100 percent confident" that Pelosi lacked the votes to remain as Democratic leader. He offered Representative Karen Bass as his first choice for Democratic leader, though Bass rejected such nomination and continued her support of Pelosi. On November 28, 2018, Pelosi easily won the Democratic nomination for Speaker of the House by a 203-to-32 vote of the Democratic caucus, with Moulton reversing himself and voting for Pelosi.

On August 24, 2021, Moulton, together with Republican representative Peter Meijer, flew unannounced into Hamid Karzai International Airport amid the evacuation of Americans and allies after the fall of Kabul. The two explained that their visit was kept secret to minimize disruption, and that its goal was "to provide guidance" to the Biden administration. Several government officials said that the surprise visit produced unhelpful distraction from the ongoing work of evacuating people. The next day, Pelosi sent a letter to all House members saying that "the Departments of Defense and State have requested that Members not travel to Afghanistan and the region during this time of danger" because such travel "would unnecessarily divert needed resources" from the evacuation efforts. Moulton defended his Kabul trip, saying, "At the end of the day, I don’t care what pundits in Washington are saying...They’ve been wrong about this war for 20 years."

Committee assignments Committee on Armed Services Subcommittee on Strategic Forces Subcommittee on Cyber, Information Technologies, and Innovation Committee on Transportation and Infrastructure Subcommittee on Highways and Transit Subcommittee on Railroads, Pipelines, and Hazardous Materials Subcommittee on Water Resources and Environment Committee on Strategic Competition between the United States and the Chinese Communist Party

Caucus memberships Congressional Arts Caucus Congressional Taiwan Caucus Black Maternal Health Caucus Congressional Equality Caucus Congressional Ukraine Caucus New Democrat Coalition Blue Collar Caucus For Country Caucus Rare Disease Caucus

Serve America PAC In 2017, Moulton founded Serve America, a political action committee that aims to help elect candidates with national service experience, focusing primarily, but not exclusively, on military service. The organization offers a network for candidates to build a community and receive advice from each other and Moulton. This was beneficial for candidates like Abigail Spanberger who said, "[Moulton has] created a network of people who are able to lean on each other, share experiences, and discuss what the campaigns are like."